The LED kits are based on 1m or 2m.
- 1m = 3 feet
- 2m = 6 feet
The hard rule for this is, if you have a Full size tower or bigger, you want to use the 2m kit. Anything smaller, like Mid towers, you want to use the 1m kit. This will offer you the best setup for the maximum about of LED lighting in your PC.